Lubricating oil containing dicyclopentadienyl iron and a wear inhibiting agent



United States Patent LUBRICATING OIL CONTAINING DICYCLO- PENTADIENYL IRON AND A WEAR INHIB- ITING AGENT Lawrence B. Scott, Lafayette, Alan C. Nixon, Berkeley, and Douglas G. Roddick, Lafayette, alif., assignors to Shell Development Company, New York, N. Y., a corporation of Delaware No Drawing. Application October 29, 1953, Serial No. 389,162

16 Claims. (Cl. 252-495) This invention relates to lubricants for use in knockinducing engines, such as spark-ignition internal combustion engines. More particularly, this invention pertains to lubricating compositions possessing knock-reducing and anti-wear properties.

In many instances it has been found desirable to add an anti-knock agent to a lubricant to act in an auxiliary capacity with a knock-inhibited fuel such as fuels containing tetraethyl lead with or without tricresylphosphate, triphenylphosphate, tributylphosphate, in order to economically and effectively increase octane requirement or aid in overcoming the maldistribution problem generally encountered in multi-cylinder engines.

Although ferrocene (dicyclopentadienyl iron) and ferrocene compounds, when added in minor amounts to lubricating oils, effectively act in the manner described above and in addition, often impart a carry-over antiknock effect in cases where ordinary fuels are used later, however, ferrocene compounds have the disadvantage of causing wear.

It has been found that lubricating compositions of this invention which contain minor, but knock-inhibiting, amounts of a ferrocene compound can be effectively inhibited against wear by addition thereto of a minor amount, generally less than about 5% by weight of a partial or full organic ester of an inorganic acid such as mono-, diand trihydrocarbyl phosphite, phosphate, phosphinate, phosphonate, arsenite, arsenate, borate, boronate, including the thio analogues, and mixtures thereof and wherein the hydrocarbyl radicals can be the same or different and includes alkyl, aralkyl, alkaryl, aryl, cycloalkyl, and the like.

Ferrocene, Fe(CsHs)z, also known as dicyclopentadienyl iron, and the preparation thereof, have been described by T. I. Kealy and T. L. Pauson, Nature, vol. 168 (1951), p. 1040. Also, R. B. Woodward et al., J. A. C. 8., vol. 74 (1952), p. 3458, have described the preparation of various derivatives of ferrocene. Other ferrocene compounds include substituted ferrocenes such as acylated, carboxylated, halogenated, alkylated, aminated and alcoholated ferrocenes, and the like. Thus, diacetylferrocene, ferrocene dicarboxylic acid, bis-(B-chloropropionyl) ferrocene, diacryloylferrocene, dichloroferrocene, tetrachloroferrocene, diaminoferrocene, dihydroxyferrocene, diethoxyferrocene, dimethylferrocene, diethylferrocene, tetraethylferrocene, diisopropylferrocene, di-n-proto be met.

\ ates, arsines; stibines; borates, boronates; silicates; tita nates; including the thio analogues and mixtures thereof and wherein the hydrocarbyl radicals can be alkyl, ar-

alkyl, alkaryl, aryl, cycloalkyl radicals which radicals can contain substituent groups such as halogens, carboxyl, amino, thioether, ether groups, and the like.

Suitable phosphorus or arsenic containing organic acids of acids of phosphorus, such as ortho-pyro-metaphosphoric and phosphorus or hypophosphorus acid: or ar senious or arsenic acids include the mono-, diand trimethyl, ethyl, propyl, butyl, phenyl, cresyl, 4-ethylpheny1, 4-tertiary-butylphenyl, xylenyl, benzyl, phenylethyl, cyclohexyl, trichlorophenyl, 4-chlorobenzylphosphites, phosphates, thiophosphites, thiophosphates, phosphines, arsenites, arsenates, thioarsenites, and thioarsenates. Preferred compounds are tricresyl phosphate, triethylphosphite, tricresyl thiophosphates, dibutyltrichloromethanephosphonate, tricresyl, arsenite, and diethylbenzenearsonate. In the case of silicate and titanates, the tetraalkyl silicates and titanates are preferred.

Esters of boric acid include triethyl, tripropyl, tributyl, tri(methylamyl), tri-n-dodecyl, tri(tetradecyl), tri(2- ethylhexyl), tricresyl, tri(tetrahydrofurfuryl), tricyclohexyl borates. Also particularly effective are the tri alkyl borates and the dialkyl esters of alkylboronic acids in which the alkyl groups attached to oxygen atoms are branched chain alkyl groups, and also the cyclic esters of boric acid or of alkaneboric acid derived from dihydric alcohols. Typical of the aforementioned trialkyl borates are the trialkyl esters of boric acid and branched chain alcohols, such as of diisopropylcarbinol and of methylisobutylcarbinol. Typical of the dialkyl esters of alkaneboronic acids is di(methylisobutylcarbinyl) methaneboronate. Typical cyclic esters of boric acid are the cyclic esters derived from boric acid and 2,4-pentanediol, pinacol, 2,4-dimethylpentane-2,4-diol or 2,4-dimethylhexane-2,4-diol. Also, there may be used the cyclic esters produced by the esterification of methaneboronic acid with diols such as 2,4-pentanediol. Another class of cyclic estersof boric acid which may be employed are:

ethyl 2,4-dimethylhexane-2,4-diol borate, ethyl pentane- 2,4-diol borate, ethyl 2,4-dimethyl pentane-2,4-diol borate,

ethyl pinacol borate and ethyl 2-methyl pentane-2,4-diol and anti-wear agents which can be incorporated into the present base compositions such as lubricating oils or fuels will depend somewhat upon the particular anti-knock compound used, the engine in which the material is to be utilized and the degree anti-knock requirement desired In general, an effective amount of each of said additives for use in lubricating oils can vary from about 0.01% to about 10% and preferably can vary from about 0.1% to about 5% by weight or as low as 0.05% and even 0.01% by weight.

The base oil of this invention in general will be a mineral lubricating oil, but various neutral or synthetic liquid materials having suitable lubricating properties are suitable for use in the compositions of the invention. Thus, the base may be a hydrocarbon oil including the paraffinic, naphthenic types as well as mixtures thereof.

The viscosity of these oils may vary over a wide range such as from 45 SUS at F. to 100 SUS at 210 F. The hydrocarbon oils may be blended with fixed oils such as castor oil, lard oil and the like and/ or with synthetic phosphonates,

If desired, the syntheticv lubricants may be used as the sole base lubricant or as' Composition A 0.5 1.0 Essentially balance Fcrrocene percent Wt Tricresylphosphate do Mineral lubricating oil Composition B 2.0 Essentially balance Dibutyl ferrocene percent wt Tricresylphosphate do Mineral lubricating oil Composition C 5 .0 Essentially balance Dibutylferrocene percent wt Triethylphosphite do Mineral lubricating oil Composition D 1.0 1.0 Essentially balance Ferrocene percent Wt Triisopropylborate do Mineral lubricating oil Composition E Ferrocene percent wt 1.2 Tri(diisopropyl carbinyl) borat'e percent Wt..- 3.0

Mineral lubricating oil Essentially balance Composition F 1.0 Essentially balance Dipropylferrocene-" percent wt Tricresyl arsenite do Mineral lubricating oil Composition G 1.5 2.0 Essentially balance Ferrocene percent wt Diethyl benzene arsenate do Mineral lubricating oil Composition H 1.2 5.0 Essentially balance Ferrocene percent wt Tricyclohexylphosphate do Mineral lubricating oil Composition I 1.6 3 .0 Essentially balance Diethylferrocene percent wt Tricresylphosphate do Mineral lubricating oil Composition J Dipropyl ferrocene percent wt 4.5 Triisopropyl phosphate do 4.0 Di-Z-ethylhexyl sebacate Essentially balance Compositions A through I showed an octane benefit varying from 2 to 18 octane numbers when tested in the CPR and Lauson engines using a primary fuel and in field tests using both a primary and secondary reference fuel. Compositions A, B, C and D were also tested in CPR and Lauson engines for wear reducing effects and wear was reduced by from 25% to 75% over a base lubricating oil or lubricating oils containing only about 1.2% ferrocene.

Compositions of this invention are particularly effective when used in combination with primary fuels such as fuels containing tetraethyl lead (TEL), iron carbonyl, with or without the added presence of organic phosphates such as tricresylphosphate, triphenylphosphates, triethylphosphites, or various combustion chamber deposit inhibitors, preignition agents, spark plug anti-foulants, antioxidants, and the like.

We claim as our invention:

1. A lubricating oil composition comprising a predominant amount of a lubricating oil and a minor but effective knock-reducing amount of a dicyclopentadienyl iron compound containing only iron, carbon and hydrogen in the molecule, and a minor, but effective wear-inhibiting amount of an oil-soluble organic ester of an inorganic acid selected from the group consisting of trihydrocarbyl phosphates, trihydrocarbyl phosphites, trihydrocarbyl arsenates, trihydrocarbyl arsenites and trihydrocarbyl borates.

2. The composition of claim 1 wherein the knock-reducing compound is an alkyl substituted dicyclopentadienyl iron.

3. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyolopentadienyl iron and a minor, but effective, wear-inhibiting amount of an oil-soluble trihydrocarbyl ester of an inorganic acid selected from the group consisting of trihydrocarbyl phosphates, trihydrocarbyl phosphites, trihydrocarbyl arsenates, trihydrocarbyl arsenites and trihydrocarbyl borates.

4. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclopentadienyl iron and a minor, but elfective, wear-inhibiting amount of an oilsoluble trihydrocarbyl phosphate.

5. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of an oil-soluble trihydrocarbyl borate.

6. A lubricating oil composition comprising a pre dominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclopentadienyl iron and a minor, but effective, Wear-inhibiting amount of an oil-soluble trihydrocarbyl arsenate.

7. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of tricresyl phosphate.

8. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclO- pentadienyl iron and a minor, but effective, wear-inhibiting amount of triisopropyl borate.

9. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of tri(diisopropylcarbinyl) borate.

10. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective, knock-reducing amount of dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of tricresyl arsenite.

11. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective knock-reducing amount of dibutyl dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of tricresyl phosphate.

12. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective knock-reducing amount of dibutyl dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of triisopropyl borate.

13. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective knock-reducing amount of dibutyl dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of tri-(disoppropylcarbinyl) borate.

14. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective knock-reducing amount of dibutyl dicyclopentadienyl iron and a minor, but effective, Wear-inhibiting amount of tricresyl arsenite.

15. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but effective knock-reducing amount of dibutyl dicyclopentadienyl iron and a minor, but effective, wear-inhibiting amount of tricresyl phosphate.

16. A lubricating oil composition comprising a predominant amount of a mineral lubricating oil and a minor, but efiective, knock-reducing amount of diisopropyl dicyclopentadienyl iron and a minor, but effective, wearinhibiting amount of tricresyl phosphate.

References Cited in the file of this patent UNITED STATES PATENTS Shappirio Aug. 27, 1935 Graves Sept. 8, 1936 Evans a- Nov. 3, 1936 Shappirio Feb. 3, 1942 Barton et a1 Feb. 24, 1953 Thomas June 8, 1954 Weinmayer July 16, 1954 

1. A LUBRICATING OIL COMPOSITION COMPRISING A PEDOMINANT AMOUNT OF A LUBRICATING OIL AND A MINOR BUT EFFECTIVE KNOCK-REDUCING AMOUNT OF A DICYCLOPENTADIENYL IRON COMPOUND CONTAINING ONLY IRON, CARBON AND HYDROGEN IN THE MOLECULE, AND A MINOR, BUT EFFECTIVE WEAR-INHIBITING AMOUNT OF AN OIL-SOLUBLE ORGANIC ESTER OF AN INORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF TRIHYDROCARBYL PHOSPHATES, TRIHYDROCARBYL PHOSPHITES, TRIHYDROCARBYL ARSENATES, TRIHYDROCARBYL ARSENITES AND TRIHYDROCARBYL BORATES. 